The major responsibility for the daily health care of a diabetic patient lies with the patient, himself. Thus, compliance is extremely crucial. Few studies have used an experimental randomized, prospective design to study compliance behavior in a diabetic population. This study proposes to use such a design in order to evaluate the effectiveness of persuasive counseling intended to increase compliance among diabetic patients. Two hundred male veterans with a diagnosis of maturity onset diabetes will be randomly assigned to the experimental or control group. A one month baseline of compliance will be established and initial interview completed. Then, the experimental subjects will undergo three sessions of persuasive counseling in their own homes. Follow up interviews will take place three and six months after intervention. Persuasive counseling is based on the health belief model and is tailored to each patient's individual set of health beliefs which include: general health motivation, perceived susceptibility, perceived severity, perceived benefits, perceived costs, and awareness of cue to action. The nurse counselor focuses on those perceptions and beliefs which seem to be preventing the subject from complying with his medical regimen. The intervention will be evaluated in terms of compliance as measured by a quantitative scale incorporating self report, medical record information, and biochemical parameters (fasting blood glucose, fasting triglyceride, 24 hour urine glucose, and glycosylated hemoglobin). Changes in health beliefs will be measured by a change score based on the interview by the nurse data collector. Univariate analysis of covariance and chi square will be used to determine differences between the experimental and control groups in terms of compliance and changes in health beliefs. Psychosocial variables including locus of control, self esteem, body image, and attitudes will also be collected once at intake into the study and correlated with the two outcome measures of compliance and changes in health beliefs. This research will provide new information regarding the effectiveness of intervention based on the health beliefs model and, more importantly, it may establish a new method for improving compliance, and therefore, the health care of diabetic patients.